ROBERTSON 3P10017 CMH0400N04932 mHID 5-Tap Ballast Kit for 400 Watt (M59) Metal Halide Lamp, 120/208/240/277/480Vac, 60Hz, CWA, HPF (Item sold now as Model CMH0400N04932 M in single quantities as ROBERTSON 3P10066) Electromagnetic Constant Wattage Autotransformer UL 1029 Component Recognized, CSA C22.2 No. 74 Certified Two Year Factory Warranty-ONLY if the Amazon Seller is ROBERTSON Worldwide. Take advantage of ROBERTSON's 60 years of electronic design and quality manufacturing experience